THE EFFECT OF SALT-INDUCED HYPERTENSION ON IMMUNE CELLS

ABSTRACT

Experimental evidence suggests that high salt diet has been shown to alter immune cells function and inflammation responses and antioxidants have been reported to alleviate hypertensive condition, however, their effects, potency and mechanisms of action have not been fully characterized. This study investigated the relationship between salt-induced hypertension and major white blood cells, immune cell function as well as pro-inflammatory cells responses and modulation by antioxidants. Thirty (30) Sprague-Dawley male rats weighing between 90 g and 110 g were allowed to acclimatize for 2 weeks thereafter, they were randomly divided into 5 groups of 5 rats each. Group 1; Control rats, received normal rat chow and tap water ad libitum. Group 2; received high salt diet of 8%NaCl (HSD) and tap water. Group 3 received HSD + high magnesium (4.8mM)/day. Group 4 received HSD + Kolaviron (200mg/kg wt/day), Group 5 received HSD + L-arginine (100mg/kg wt/day). Feeding and drug administration were by oral gavage for 6 weeks. Blood pressure (BP) (mmHg), heart rate (bpm) and weight measurement was done before the commencement of treatment by cuff tail artery. Thereafter, measurement was done weekly till the end of 6-week period. 24 hours after the last administration, animals were humanely sacrificed using chloroform anaesthesia. 5 mls blood sample was collected via cardiac puncture for serum analysis of blood parameters. Mean arterial pressure (MAP) significantly increased from 5th week compared with the control whereas the antioxidative agents (Magnesium, kolaviron, and Larginine) attenuated increase in MAP when compared to high salt diet fed. Monocytes level was significantly decreased in HSD + (kolaviron and Larginine compared with HSD only. but there were no significant differences between HSD + high magnesium and HSD fed rats. P<0.05; There were no significant changes in other white blood cells types in the test groups compared to the control. There was a strong positive correlation between the 10 Cyclooxygenase-2 and WBC whereas interleukin 10 (IL-10) showed negative correlation with WBC in salt-induced hypertensive rats. In conclusion, increase in mean arterial pressure in pre-hypertensive salt-loaded Sprague-Dawley rats was modulated by antioxidants. Furthermore, salt-induce hypertension indicates some positive correlation with WBC, Cyclooxygenase-2 and granulocytes in Sprague-Dawley rats.